CORE 1 SUMMARY/ABSTRACT Core 1, ?Administration and Biostatistics,? provides the Administrative and Statistical support for the entire PPG. The core supports a Scientific Advisory Board that monitors PPG progress on yearly basis. Dr. Steven Burakoff and Dr. Miriam Merad, both faculty members of the Icahn School of Medicine at Mount Sinai, and Dr. Thomas Braun, lead statistician of the PPG for the past two cycles, have become additional members of the scientific advisory board. Dr. Burakoff, the director of the Tisch Cancer Institute and original PI of this PPG at its inception thirty years ago, will serve as interim PPG director in the event that Dr. Ferrara should be unable to continue in his role. Dr. Burakoff will chair the executive committee until it selects a permanent successor with advice of the SAB, subject to approval by the NCI. This core provides biostatistical support for all three projects. Dr. Umut Ozbek of the Icahn School of Medicine at Mount Sinai has replaced Dr. Braun as lead statistician. We have made this change after careful consideration of the many other changes in the PPG, most important of which is the recruitment to Mount Sinai of Dr. John Levine, Project 3 Leader of Director of Core 3. The extensive collaborations over the past two cycles with Dr. Braun, particularly as they relate to the sophisticated analyses required in the development of algorithms needed to determine eligibility criteria for clinical trials, impressed upon the executive committee the need for iterative, face-to-face meetings that include Drs. Levine and Ferrara as well as the lead statistician who can devote sufficient time to this project. Because all three Core directors and two of three Project Leaders are located at Mount Sinai, we have developed a new collaboration with Dr. Ozbek who will serve as a lead statistician at Mount Sinai. Over the past year Ozbek has engaged admirably with the statistical issues that are central to the PPG, and in addition to numerous meetings with Drs. Ferrara and Levine, she had attended Dr. Ferrara's laboratory meetings and several journal clubs that have analyzed the BMT clinical trial data. She also reviewed in depth the clinical trial proposed in Project 3 and now serves as the statistician of record for that trial. In addition, she has used new approaches to the definition of thresholds to define risk strata by biomarkers with unsupervised machine learning techniques. Using the same algorithm, these techniques have led to better classification of patients with moderate risk and identified additional patients at high risk who would be eligible for clinical trials. We have included these data as examples of the types of the types of analyses that enhance the science within the PPG. This core also provides communication among PPG personnel and coordinates their interactions to ensure optimal integration of all Projects and Cores. We have made more explicit the mechanisms that coordinate the communication among the different sites, including the bi weekly webinars where GVHD clinical symptoms are reviewed and compared. These webinars also review reports of BMT outcomes including GVHD rates, non relapse mortality and overall survival that are created by our new statistician, Dr. Ozbek. We have also provided greater details regarding the logistical preparation for the annual MAGIC symposium, where PIs from all eleven sites gather at the Icahn School of Medicine at Mount Sinai to discuss priorities for the consortium in the upcoming year.